I use newtx and newtxmath in pdflatex with TeXLive, but I would like to use the \mathcal{O} symbol from Latin Modern. Following this answer, I am able to access the medium-series version. In the preamble, I add


And then in the document, I can use e.g. $\lmO (N^{2})$.

But I would also like to use the boldface version of that symbol. Preferably it should work automatically with \bm, but if that is too hard, I wouldn't mind having simply a macro for it, e.g. \lmBO. However, the following attempt


returns the warning

   LaTeX Font Warning: Font shape `OMS/lmbsy/b/n' undefined
   (Font)              using `OMS/cmsy/m/n' instead on input line 30.

Note that \fonttable{lmbsy10} does print out, on my system, all the expected symbols, including the boldfaced mathcal O.

How do I access the boldfaced mathcal O from Latin Modern (while usingnewtxmath for all other math)? If possible, how to make this Latim Modern mathcal O work with \bm?


1 Answer 1


Use \SetSymbolFont to declare the font for math version bold.

\usepackage{newtxtext, newtxmath}


\[ O \quad \mathcal{O} \quad \mscrO \quad \boldsymbol{\mscrO}

Latin Modern + NewTx sample

You might also declare \newcommand\mbfscrO{\boldsymbol{\mscrO}} for convenience and compatibility. I’m not sure whether giving this symbol the spacing of a binary operator was intentional, but if it was, you can easily change it back. You can optionally \usepackage{bm} after all your other math commands.

In unicode-math, you can override this symbol for both \mathcal and \mathbfcal with the range= option of \setmathfont, so:

\setmathfont{TeX Gyre Termes Math}[Scale=MatchUppercase]
\setmathfont{Latin Modern Math}[Scale=MatchUppercase,

You can then use \mbfscrO, \mathbfcal{O}, and a few other synonyms.

  • And I see @egreg posted this as a comment while I was writing my MWE.
    – Davislor
    Sep 14, 2021 at 16:05
  • That worked, including with \bm. Thanks! Sep 14, 2021 at 16:06

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